The present invention relates generally to circuit modules and, more particularly, to a memory card (e.g., a multi-media card (MMC)) comprising a leadframe implanted into a plastic body such that a semiconductor die is mounted in a downward configuration with respect to the connector of the card.
As is well known in the electronics industry, circuit modules or cards are being used in increasing numbers to provide memory storage and other electronic functions for devices such as digital cameras, MP3 players, cellular phones, and personal digital assistants. In this regard, circuit modules are currently used in various memory card formats, including multi-media cards and secure digital cards.
Typically, circuit modules include multiple integrated circuit devices or semiconductor dies. The dies are interconnected using a circuit board substrate which adds to the weight, thickness, stiffness and complexity of the module. Circuit modules also include electrical contacts for providing an external interface to an insertion point or socket. These electrical contacts are typically disposed on the back side of the circuit board substrate, with the electrical connection to the dies being provided by vias which extend through the circuit board substrate.
In an effort to simplify the process steps needed to fabricate the circuit module and, hence, the memory card using the same, there has been developed by Applicant a circuit module wherein a leadframe assembly is used as an alternative to the circuit board substrate, as described in Applicant's co-pending U.S. application Ser. No. 09/956,190 entitled LEAD-FRAME METHOD AND ASSEMBLY FOR INTERCONNECTING CIRCUITS WITHIN A CIRCUIT MODULE filed Sep. 19, 2001, the disclosure of which is incorporated herein by reference. As is described in Ser. No. 09/956,190, the leadframe and semiconductor die of the circuit module may be covered with an encapsulant which hardens into a cover or body. The body is sized and configured to meet or achieve a “form factor” associated with the memory card. In the completed memory card, the contacts of the leadframe are exposed within a common surface of the body, with a die pad of the leadframe and the semiconductor die mounted thereto being disposed within or covered by the body.
It has been found that the molding or encapsulation process sometimes gives rise to structural deficiencies or problems within the resultant memory card. These problems include portions of the die pad of the leadframe being exposed within the memory card, flash being disposed on the contacts of the leadframe, chipping in a peripheral flange area of the body, and mold gate pull-out wherein a portion of the mold or encapsulating compound is pulled out from within the body leaving a small recess or void therein. The present invention addresses these problems by providing a memory card having a “die down” configuration attributable to the structural attributes of the leadframe included therein, and an associated molding methodology employed in the fabrication of such memory card. These, as well as other features and attributes of the present invention, will be discussed in more detail below.